Devices for directionally controlling the transmission of a laser beam have been adapted for medical procedures. Lasers offer the advantages of high power and narrow spectral widths for producing small focused spot sizes on the target. Furthermore, target tissues readily absorb the laser energy.
The Argon laser (blue-green) has been extensively used in ophthamology because it provides good transmission characteristics in the ocular media as well as good absorption by target tissues in the retina and choroid. However, the carbon dioxide (CO.sub.2) laser is highly absorbed by all tissues in the body and therefore offers the most extensive range of applications in medicine. A lens may be used to focus or defocus the laser beam depending on the application, such as photocoagulation of vessels and arteries, cutting, or vaporization of almost any body tissue including tumors and other abnormal tissues. The CO.sub.2 laser has been applied in a number of medical disciplines including otolaryngology, gynecology, neurology, dermatology and in plastic and general surgery.
Heretofore, devices for realigning or manipulating a laser beam for medical or commercial applications may include one or more mirrors for redirecting or controlling the transmission path of the laser beam, while in other applications it may be necessary to manipulate the beam throughout its use in the procedure. For example, in lapraroscopy or bronchoscopy, it may be necessary to realign the laser beam to align or center the beam with an endoscope for proper entry therein. Laser beam realignment may be especially necessary when the beam is reflected from a number of mirrors in the transmission path. In contrast, it may be necessary to manipulate the laser beam during use to perform, for example, tumor evaporation or medical or commercial cutting procedures.
The last mirror or only mirror in the transmission path may be adjustably mounted in a fixture for adjusting the mirror position to direct or redirect the laser beam to the target site. When precision adjustment is desired, a joy stick may be linked with the above-mentioned mirror. Furthermore, the realigning or manipulating mirror may be positioned within a housing which also may include one or more lenses for focusing or defocusing the beam. An adapter may also be provided on the housing to connect the housing, for example, to an endoscope.
After continued use wherein the mirror receives a concentrated beam of energy in the form of a laser beam, the mirror becomes stained or discolored. Consequently, the hot mirror should be cleaned or more appropriately replaced. Unfortunately, prior art laser manipulators include complex mechanisms, such as gimbal assemblies, for fixedly positioning the adjustable mirror in a housing. These complex linkages operatively associate the mirror and the housing to form a mechanism therebetween for manipulating the mirror. Consequently, it is difficult to disassemble these complex linkages when it is necessary to remove the mirror assembly for cleaning or replacement thereof. Furthermore, these complex linkages are no less difficult to assemble during manufacture.